Secondary or storage battery.



N. DODGE.

SECONDARY OE STORAGE BATTERY.

APPLICATION FILED JUNE-19, 1904.

1,000,330, Patented Aug. 8,1911.

' forth, theinvention, stated in general terms, 7 comprises the improvements to be-presently UNITED STATES PATENT OFFICE.

NORMAN DODGE, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOB TO THE ELECTRIC STORAGE BATTERY COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORA- TION OF NEW JERSEY.

SECONDARY 0R STORAGE BATTERY.

Specification of Letters Patent.

Application filed June 9, 1904. Serial No. 211,739.

citizen of the United States, residing at the city of Philadelphia, in 'the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Secondary or Storage Batteries, of which the following is a specification.

The object of the present invention is to provide a satisfactory and eflicient wood separator and to provide for treating the same in such a way as to make it practically successful in its application to lead storage batteries.

To this and other ends hereinafter set described and finally claimed.

The nature, characteristic features and scope of my invention will be more fully understood from the following description taken in connection with the accompanying drawings forming part hereof and in which- Figure 1, is an elevational view and Fig. 2, is a sectional view of a storage battery embodyingfeatures of the invention.

In the drawings a, is a storage battery separator consisting of wood adapted to constitute a diaphragm impervious to battery sediment. pine, poplar and Oregon me are types of such wood. The shape 0 the separator a, shown in the drawings is merely selected for illustration and the typeand arrange-1 .ment of the plates b and 0,. are likewise illustrative only. These details form no part of the invention.

The wood separator which is adapted to constitute a diaphragm impervious to "battery sediment is primarily deprived of such of its constituents and wood acids as would in the operation of a battery attack lead. Acetic acid is a type ofthe wood acids referred to and if the latterwere present they would in the'operation of the battery either attack the positive lead pole plate causing its disintegration or perhaps by oxidation escape without doing injury, but

Bass, birch, cherry, white.

the only successful course is to primarily Patented Aug. 8, 1911.

deprive the wood of such acids. There are two Ways of treating the wood for the accomplishment of this result. First, the wood is soaked in a sulphuric acid water solution, of, for example, 1.2 specific gravity at normal temperature for two days, more or less. If the solution is heated, for ex; ample to 100 degrees .F. weaker acid can be used, for example, 1.1 specific gravity,

-the duration of the treatment being about the same, and second; the wood is soaked in an alkaline solution such as a 3% solution of caustic potash at normal temperature for about 24 hours. Subsequently the wood is washed as in running water for 48 .hours', more or less. Onepdund of the dry I alkali" is sufficient for treating five pounds line solution is to remove from the wood those acids or constituents which in the use of the battery are likely to attack and'disintegrate the lead of the positive pole plate. Although the wood is by the described treatment deprived of certain of its constituents, still it retains others of its con stituents, some or all of which beneficially affect the operation of the battery, more particularly in respect to the capacity and "life of the negative pole plates. The treated wooden separators are characterized by the property of warping, shrinking, curling and splitting when dry so that they are kept wet or impregnated with moisture until they areplaced in the battery liquid.

It will be obvious to those skilled in the art to which my invention relates that modifications may Joe made in details without deartin from the spirit thereof, hence the inventlon 'is not limited otherwise than as the prior state of the art may require, but

Having thus described the nature and objects of my invention, what I claim as new; and desire to secure by Letters Patent isz A storage battery separator consisting f a sheet of fine grain wood having its natural structure and containing its cellulpse and fibrous constituents and constituting a dia- In testimony whereof I have hereunt phragm impervious to battery sediment and signed my name. primarily deprived of such of its constituents as would deleteriously attack lead NORMAN DODGE When subjected to electrolytic action and Witnesses: retaining such 'of its constltuents as bene- W. J. JAcKsoN,

ficial ly afiect a negative pole plate. I FRANK E. FRENCH.- 

